Alpha Radiation Can Damage DNA Even When It Misses the Cell Nucleus

Physics Today ◽  
1999 ◽  
Vol 52 (9) ◽  
pp. 19-20 ◽  
Author(s):  
Charles Day
Keyword(s):  
2014 ◽  
Vol 881-883 ◽  
pp. 360-363
Author(s):  
V.V. Dyachkov ◽  
Y.A. Zaripova ◽  
N.G. Riger ◽  
A.L. Shakirov ◽  
A.V. Yushkov

The paper describes biophysical processes occurring in membranes under the influence of alpha-radiation of radon isotopes. The basic idea is to experimentally detect the effects of radiation damage to cells of the α-particle with energy of 5.5 MeV, and in particular, to determine the dependence threshold in a function of the "dose-effect" in the presence of DNA molecules into cells. Actuality of work related to the fact that up to now remains open the problem – is whether damageability of radioactive radiation threshold or without threshold phenomenon. It was found that the irradiation of biological models of cells - liposomes and spherosomes uniquely showed the lack threshold of damageability. Irradiation red blood cells not having a cell nucleus, occurs as a threshold phenomenon. Finally, the irradiation of the lactic acid bacteria occurs with a high threshold


Author(s):  
D.L. Spector ◽  
S. Huang ◽  
S. Kaurin

We have been interested in the organization of RNA polymerase II transcription and pre-mRNA splicing within the cell nucleus. Several models have been proposed for the functional organization of RNA within the eukaryotic nucleus and for the relationship of this organization to the distribution of pre-mRNA splicing factors. One model suggests that RNAs which must be spliced are capable of recruiting splicing factors to the sites of transcription from storage and/or reassembly sites. When one examines the organization of splicing factors in the nucleus in comparison to the sites of chromatin it is clear that splicing factors are not localized in coincidence with heterochromatin (Fig. 1). Instead, they are distributed in a speckled pattern which is composed of both perichromatin fibrils and interchromatin granule clusters. The perichromatin fibrils are distributed on the periphery of heterochromatin and on the periphery of interchromatin granule clusters as well as being diffusely distributed throughout the nucleoplasm. These nuclear regions have been previously shown to represent initial sites of incorporation of 3H-uridine.


Author(s):  
David L. Spector ◽  
Robert J. Derby

Studies in our laboratory are involved in evaluating the structural and functional organization of the mammalian cell nucleus. Since several major classes (U1, U2, U4/U6, U5) of small nuclear ribonucleoprotein particles (snRNPs) play a crucial role in the processing of pre-mRNA molecules, we have been interested in the localization of these particles within the cell nucleus. Using pre-embedding immunoperoxidase labeling combined with 3-dimensional reconstruction, we have recently shown that nuclear regions enriched in snRNPs form a reticular network within the nucleoplasm which extends between the nucleolar surface and the nuclear envelope. In the present study we were inte rested in extending these nuclear localizations using cell preparation techniques which avoid slow penetration of fixatives, chemical crosslinking of potential antigens and solvent extraction. CHOC 400 cells were cryofixed using a CF 100 ultra rapid cooling device (LifeCell Corp.). After cryofixation cells were molecular distillation dried, vapor osmicated, in filtra ted in 100% Spurr resin in vacuo and polymerized in molds a t 60°C. Using this procedure we were able to evaluate the distribution of snRNPs in resin embedded cells which had not been chemically fixed, incubated in cryoprotectants or extracted with solvents.


2019 ◽  
Author(s):  
C Kratochwil ◽  
CP Heussel ◽  
F Bruchertseifer ◽  
U Haberkorn ◽  
A Morgenstern ◽  
...  

Acta Naturae ◽  
2017 ◽  
Vol 9 (4) ◽  
pp. 42-51
Author(s):  
S. S. Ryabichko ◽  
◽  
A. N. Ibragimov ◽  
L. A. Lebedeva ◽  
E. N. Kozlov ◽  
...  

2020 ◽  
Vol 7 (2) ◽  
pp. 21-28
Author(s):  
SALI RADZHAPOV ◽  
◽  
RUSTAM RAKHIMOV ◽  
BEGJAN RADZHAPOV ◽  
MARS ZUFAROV

The article describes the developed radiometer for Express measurement of alpha radiation of radioactive elements based on a large-diameter silicon detector. The main element of the PPD detector is made using computer mathematical modeling of all stages of the technological process of manufacturing detectors, taking into account at each stage the degree of influence of the properties of the initial silicon on the electrophysical and radiometric characteristics of the detector. Detectors are manufactured for certain types of devices. The developed radiometer is designed to measure alpha radiation of natural isotopes (238U, 234U, 232Th, 226Ra, 222Rn, 218Po, 214Bi, etc.) in various environments. It also shows the principle of operation of the device, provides a block diagram of the measuring complex, describes the electronic components of the radiometer, as well as the block diagram. Signal transformations (spectrum transfer, filtering, accumulation) are implemented programmatically on the basis of a digital processing module. The device can detect the presence of specific elements in various environments, as well as protect people from the harmful effects of adverse radiation and can be used both in the field and stationary.


2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Ruswana Anwar ◽  
Muhammad Alif ◽  
Adhi Pribadi

Endometriosis is one of the most common gynecological problem. Cells resulted in chronic inflammation and progressive, proliferative, invasive and even infiltrating an area that resembles the character of the malignancy. Ki-67 is an antigen on the cell nucleus that is found only in actively dividing cells. Expression of Ki-67 are associated with an aggressive tumor and metastasis. This study aims to determine the level of Ki-67 expression correlation with stage and size of the endometriosis cyst. Methods research is observational analytic cross cut method on 56 paraffin blocks of patients who have been diagnosed with endometriosis and had performed a laparotomy or laparoscopic surgery in Dr Hasan Sadikin Hospital. The results showed a significant relationship between the level of expression of Ki-67 with endometriosis cyst size (p <0.001) with a fairly strong relationship (0.55) according to statistics based on criteria Guilford. Moreover the results also showed a significant relationship between the level of expression of Ki-67 with endometriosis stage (p <0.001) with a fairly close relationship (0.564) according to statistics based on criteria Guilford. It can be concluded that the expression of Ki-67 associated with cyst size and stage of endometriosis. Keywords: Ki-67, endometriosis stage, endometriosis cyst


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